Numbers of the form q*(2^k), where q is one of the Mersenne primes (A000668) and k >= 0.

Terms

a(0) =3a(1) =6a(2) =7a(3) =12a(4) =14a(5) =24a(6) =28a(7) =31a(8) =48a(9) =56a(10) =62a(11) =96a(12) =112a(13) =124a(14) =127a(15) =192a(16) =224a(17) =248a(18) =254a(19) =384a(20) =448a(21) =496a(22) =508a(23) =768a(24) =896a(25) =992a(26) =1016a(27) =1536a(28) =1792a(29) =1984